package com.heima.sample;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.common.TopicPartition;

import java.time.Duration;
import java.util.Collections;
import java.util.Map;
import java.util.Properties;

/**
 * 消费者
 */
public class ConsumerQuickStart {
    public static void main(String[] args) {
        //1.添加kafka的配置信息
        Properties properties = new Properties();
        //kafka的连接地址
        properties.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.88.2:9092");
        //消费者组
        properties.put(ConsumerConfig.GROUP_ID_CONFIG, "consumerGroup2");
        //手动提交偏移量
        properties.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, "false");
        //消息的KEY-VALUE反序列化器
        properties.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        properties.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");

        //2.消费者对象
        KafkaConsumer<String, String> consumer = new KafkaConsumer<String, String>(properties);

        //3.订阅主题
        consumer.subscribe(Collections.singletonList("itcast-topic-output"));

        //当前线程一直处于监听状态
//        while (true) {
//            //4.获取消息
//            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
//            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
//                System.out.println("key:"+consumerRecord.key());
//                System.out.println("value:"+consumerRecord.value());
//                System.out.println("offset:"+consumerRecord.offset());
////                try {
////                    //同步提交偏移量
////                    consumer.commitSync();
////                }catch (Exception e){
////                    System.out.println(e.getMessage());
////                }
//                //当前分区的分区号
//                System.out.println("partition:"+consumerRecord.partition());
//            }
//            //异步提交偏移量
//            consumer.commitAsync(new OffsetCommitCallback() {
//                @Override
//                public void onComplete(Map<TopicPartition, OffsetAndMetadata> map, Exception e) {
//                    if (e != null) {
//                        System.out.println("记录错误的提交偏移量:" + map+ ",异常信息为:"+e);
//                    }
//                }
//            });
//        }
        try {
            while (true) {
                ConsumerRecords<String, String> records = consumer.poll(Duration.ofMillis(100));
                for (ConsumerRecord<String, String> record : records) {
                    System.out.println("key:" + record.key());
                    System.out.println("value:" + record.value());
                    System.out.println("offset:" + record.offset());
                    System.out.println("partition:" + record.partition());
                }
                //异步提交偏移量
                consumer.commitAsync();
            }
        }catch (Exception e) {
            System.out.println("异常信息为:"+e);
        }finally {
            try{
                //异步提交出错时，在使用同步提交方式
                consumer.commitSync();
            }catch (Exception e){
                e.printStackTrace();
            }
        }
    }
}
